JONATHAN TURLEY IN THE HILL: FBI source in Russia probe raises alarms over political surveillance. “Three questions, however, stand out over his role. The details of Halper’s work still are largely unknown. What we know is that the FBI carried out an investigation targeting Trump campaign officials with both surveillance, document demands, and at least one informant. All of this was done through national security powers, where warrants are easily obtained and kept secret. We know this investigation began, at the latest, in July 2016 and that the Foreign Intelligence Surveillance Act application was based in part on a dossier paid for by the Clinton campaign. We also know that key Justice Department officials expressed hostile views of Trump in emails, and that key Justice Department officials have been subjects of demotions and one criminal referral. . . . While the media has tended to downplay these allegations, they are manifestly serious. The use of a paid FBI asset to target a national campaign in this way would be unprecedented. The closest we have come historically was the allegation in 1980 that aides to Ronald Reagan spied on Jimmy Carter’s campaign and obtained confidential documents Carter used to prepare for a debate. While he has denied the allegations, one of those aides identified was Halper.”